The search engine giant said on its website that the service now automatically scans sent or received messages for malicious software.
"If a virus is found in an attachment you've received, our system will attempt to remove it, or clean the file, so you can still access the information it contains," the company said on the GMail website. "If the virus can't be removed from the file, you won't be able to download it."
"If a virus is found in an attachment you're trying to send, you won't be able to send the message until you remove the attachment." GMail had, until the addition of virus scanning, blocked messages that the service had thought contained viruses.